mysql> SHOW GRANTS FOR 'root'@'localhost';
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@localhost                                                                                                                                                                                                                                                                                                                     |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER ON *.* TO 'root'@'localhost' WITH GRANT OPTION |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> GRANT ALL ON *.* TO 'root'@'localhost';
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
mysql>

mysql> select Grant_priv, Super_priv from user where User='root';
+------------+------------+
| Grant_priv | Super_priv |
+------------+------------+
| Y          | Y          |
+------------+------------+
1 row in set (0.00 sec)

mysql>